I would add a different way to make sense of it.

Proof of work allows for what Keynes called "Bancor". BTC is succesful because unlike fiat central banks, the money supply isn't dictated by interest rates (and thus loans) but by the effort of participants. The price of BTC is almost irrelevant, BTC itself is a paradigm shift.

Regarding the fixed supply, it's only fixed because participants agree to the consensus algorithm that fixes it. Many cryptocurrencies have different tokenomics, such as ETH's rules under PoS. BTC miners could vote onchain for a hard fork to change the 21M cap - or another solution.